Fiber Optic LED Driver
Description
March 1997
ML4632 Fiber Optic LED Driver
GENERAL DESCRIPTION
The ML4632 is a fiber optic LED driver suited for network applications up to 20Mbps.
The part is capable of driving up to 100mA of current through a Fiber Optic LED from an ECL or TTL level input signal.
Its efficient output stage provides a high current that can be programmed for accurate absolute output level as well as automatic temperature compensation.
The combination of automatic temperature compensation and a highly accurate current driven design insures precise launch power.
The LED driver’s output stage provides fast, well matched rise and fall times through a unique class B output stage that burns supply current only when the LED is on.
A positive temperature coefficient of up to 3300ppm/°C can be programmed into the output current to compensate for the negative temperature coefficient of the LED optical output power.
An optional peaking circuit may also be employed.
The ECL and TTL inputs are ANDed so one can be used for data and the other for an enable input.
An ECL compatible BIAS voltage is also provided for single ended ECL applications.
FEATURES
s s s s s s s s
Current Driven Output for accurate Launch Power Programmable output current from 20mA to 100mA Programmable temperature coefficient, 0 to 3300ppm/°C High Efficiency Output Stage Programmable LED pre-bias current Low EMI/RFI Noise ECL or TTL inputs Optional Peaking circuit
APPLICATIONS
s s s s
IEEE 802.
3, 10BASE-F IEEE 802.
5 Fiber Optic Token Ring IEEE 802.
4 Fiber Optic Token Bus Fiber Optic Data Communications and Telecommunications
BLOCK DIAGRAM
ECLP 14 ECLN 1
+ BUFFER – PEAK
7
PEAK
6
RPK
VBIAS
2 3 LED DRIVER 5 RTSET
TTL 13
VCC
8
DRV AMP REF PTAT
11 DRV
10 VREF 12 PTAT
GND
4 9 IOFF
1
ML4632
PIN CONFIGURATION
ML4632 14-Pin PDIP (P14)
ECLN VBIAS LED GND RTSET RPK PEAK 1 2 3 4 5 6 7 14 13 12 11 10 9 8 ECLP TTL PTAT DRV VREF IOFF VCC
ML4632 16-Pin Wide SOIC (S16W)
ECLN VBIAS LED GND RTSET RPK PEAK NC
1 2 3 4 5 6...
Similar Datasheet
